Sleep means now more than ever- remember that even during finals week
You can do anything you want, but not everything you want
Establish relationships with people in your classes. You may only be with them for the semester, but you never know when they might be helpful for you later on.
Talk to your professors. So much more of what they do is just teach. Most of them are conducting research and well-respected enough in their communities to give talks at conferences and other universities. Students who take the time to get to know more about who they are and what their passions are will be more valuable to them and much appreciated.
Understand the art of networking as soon as possible. Establishing connections is crucial.